SOLUTION: w²-9w+7 I just seem to be stuck on this one its questions 19 of 20 and of course it had to trip me up

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Question 195287: w²-9w+7
I just seem to be stuck on this one its questions 19 of 20 and of course it had to trip me up
Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
you dont have instructions on this so I will treat it like a quadratic equation
:
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 1x%5E2%2B-9x%2B7+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%28-9%29%5E2-4%2A1%2A7=53.

Discriminant d=53 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28--9%2B-sqrt%28+53+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%28-9%29%2Bsqrt%28+53+%29%29%2F2%5C1+=+8.14005494464026
x%5B2%5D+=+%28-%28-9%29-sqrt%28+53+%29%29%2F2%5C1+=+0.859945055359741

Quadratic expression 1x%5E2%2B-9x%2B7 can be factored:
1x%5E2%2B-9x%2B7+=+%28x-8.14005494464026%29%2A%28x-0.859945055359741%29
Again, the answer is: 8.14005494464026, 0.859945055359741. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B-9%2Ax%2B7+%29